Optimal Service Upgrade of a Cluster

In This Section: Supported Versions for Optimal Service Upgrade Optimal Service Upgrade Limitations Optimal Service Upgrade of a Security Gateway Cluster Optimal Service Upgrade of a VSX Cluster Troubleshooting the OSU Upgrade

Use the Optimal Service Upgrade (OSU) method to upgrade a Security Gateway Cluster or a VSX Cluster. This procedure lets you upgrade the cluster with a minimum loss of connectivity.

When you upgrade the cluster, two Cluster Members are used to process the network traffic. New connections that are opened during the upgrade procedure are maintained after the upgrade is finished. Connections that were opened on the old version are discarded after the upgrade.